21345629 has 2 divisors, whose sum is σ = 21345630. Its totient is φ = 21345628.

The previous prime is 21345619. The next prime is 21345637. The reversal of 21345629 is 92654312.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 12924025 + 8421604 = 3595^2 + 2902^2 .

It is a cyclic number.

It is not a de Polignac number, because 21345629 - 2¹² = 21341533 is a prime.

It is a Chen prime.

It is a junction number, because it is equal to n+sod(n) for n = 21345595 and 21345604.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21345619) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10672814 + 10672815.

It is an arithmetic number, because the mean of its divisors is an integer number (10672815).

Almost surely, 2^21345629 is an apocalyptic number.

It is an amenable number.

21345629 is a deficient number, since it is larger than the sum of its proper divisors (1).

21345629 is an equidigital number, since it uses as much as digits as its factorization.

21345629 is an evil number, because the sum of its binary digits is even.

The product of its digits is 12960, while the sum is 32.

The square root of 21345629 is about 4620.1330067434. The cubic root of 21345629 is about 277.3977828762.

The spelling of 21345629 in words is "twenty-one million, three hundred forty-five thousand, six hundred twenty-nine".